PROJECT SUMMARY Career Goal: My long-term research goal is to identify features of the early social communication environment that are early intervention targets for infants that go on to have autism spectrum disorder (ASD). The overall objective of this application, which is the next step toward attainment of my long-term goal, is to determine which aspects of the early social communication environment are protective factors for brain development and behavioral outcome. Research Project: Children with ASD who grow up in rich social communication environments show superior language abilities later in life when compared to children who grow up in less rich social communication environments; however, to date it is unknown if the social communication environment from birth to two years impacts brain development and behavioral outcome in infants at high-familial risk for ASD. Given that the first year of life is a time of great brain plasticity and before the emergence of the diagnostic features of ASD, determining early influential brain mechanisms and intervening during this time could yield ideal outcomes. The goal of the current project is to determine if a rich early social communicative environment supports optimal brain and behavioral development in infants at high-risk for ASD who do and do not go on to develop ASD. Additionally, an independent sample of infants will be studied to determine optimal periods for intervention by searching for time-dependent associations between the social communication environment and brain/behavior development. Specific Aims: 1) To define patterns of association between the early social communication environment with language and brain development in infants at low-risk for ASD. (K99); 2) To determine if the early communication environment is a protective factor for brain development and autism symptoms in infants at high-risk for ASD. (K99); 3) To identify the time window when the association between the social communication environment and infant brain development is the strongest. (R00). Career Development: This K99/R00 award will provide the necessary training I require before transitioning into an independent position including: mastering advanced diffusion tensor imaging analytic techniques, becoming proficient in structural magnetic resonance imaging, training in MRI acquisition of infant neuroimaging data, gaining skills in the application of novel computer algorithms to automatically characterize the social communication environment, and completing training in advanced statistical approaches to investigate environment-brain-behavior relationships. Mentorship: To support my training and career development a highly accomplished, multidisciplinary team has agreed to provide mentorship. My mentoring team includes a primary mentor, Dr. Joseph Piven (Dept. of Psychiatry, UNC), a secondary mentor, Dr. Martin Styner (Dept. of Computer Science, UNC), and two complimentary collaborators: Drs. James Rehg (School of Interacting Computing, Georgia Tech), and Jonathan Green (Institute of Brain, Behaviour, and Mental Health, University of Manchester).